a ravenous appetite的用法和样例：
- Most infants have a ravenous appetite.
- A meal had been prepared. I fell to with ravenous appetite.
- A meal had been prepared; I fell to with ravenous appetite.
- A raven perched high in the pine.
- Nourish a raven and he will scratch out your eyes.
- Very soon he heard a raven cry outside.